1001212021 has 4 divisors (see below), whose sum is σ = 1016155552.
Its totient is φ = 986268492.
The previous prime is 1001212019. The next prime is 1001212067. The reversal of 1001212021 is 1202121001.
It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.
It is a cyclic number.
It is not a de Polignac number, because 1001212021 - 21 = 1001212019 is a prime.
It is a Duffinian number.
It is a junction number, because it is equal to n+sod(n) for n = 1001211989 and 1001212007.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (1001212081) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (17) of ones.
It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7471665 + ... + 7471798.
It is an arithmetic number, because the mean of its divisors is an integer number (254038888).
Almost surely, 21001212021 is an apocalyptic number.
It is an amenable number.
1001212021 is a deficient number, since it is larger than the sum of its proper divisors (14943531).
1001212021 is an equidigital number, since it uses as much as digits as its factorization.
1001212021 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 14943530.
The product of its (nonzero) digits is 8, while the sum is 10.
The square root of 1001212021 is about 31641.9345331476.
The cubic root of 1001212021 is about 1000.4038438882.
Adding to 1001212021 its reverse (1202121001), we get a palindrome (2203333022).
It can be divided in two parts, 100 and 1212021, that added together give a palindrome (1212121).
The spelling of 1001212021 in words is "one billion, one million, two hundred twelve thousand, twenty-one".